Bark components as resin ingredients



1956 R. D. PAULEY BARK COMPONENTS AS RESIN INGREDIENTS Filed May 4, 1954 550mm. xadm Z. XUOU p 9 mcsa 0003 XEOU wk xmo waa KwnBQ maQl 0m I O0 1 0 3 I QM a GM I 0% I Ob OU United States Patent() 2,773,847 Pa..,. d' ec.1;1,

BARK COMPONENTS AS RESIN INGREDIENTS Robert D. Pauley, Tacoma, Wash, assignor to Weyerhaeuser Timber Company, Tacoma, Wash., a corporation of Washington Application May 4, 1954, Serial No. 427,580

10 Claims. (Cl. 26017.2)

This invention is concerned with the reaction of the cork and parenchyma components of the bark of coniferous trees with a basic acting alkaline compound to render the cork and parenchyma components reactive with an aldehyde to form a resin. It is the discovery of this invention that fractions of the bark of trees, containing the cork component in a proportion of at least about 68%, the remainder being parenchyma tissue or bark fiber or mixtures of both, may be activated by reaction with a soluble alkaline reacting compound and thereby be made reactable with aldehydes to produce a thermosetting resin which may be used in addition to phenolic compounds or to replace phenolic compounds in phenolaldehyde type resins. Among such uses are the making of molded products, adhesive compositions and structural hardboards.

This application is a continuation in part of my copending application Serial No. 257,981, filed November 23, 1951, for Bark Components as Resin Ingredients, which was continued from application Serial No. 36,409, filed July 1, 1948, now abandoned.

It is an object of this invention to make a bark derived resin substitute for phenol-aldehyde resins, which resin has properties similar to phenol-aldehyde resins.

Various other and ancillary objects and advantages of the present invention will become apparent from the following description and explanation of the present invention.

Bark is not a homogeneous material, but is composed primarily of three difierent tissue components, to-wit: cork, sclerenchyma tissue in the form of either bast fibers or stone cells, and parenchyma tissue made up chiefly of sieve tubes but containing also food storage cells, companion cells, and connecting ray tissues. The term non-fibrous phloem used herein refers broadly to that portion of the whole bark from which a substantial portion of the cork and the sclerenchyma tissue has been removed. It, therefore, includes parenchyma tissue and may also include small proportions of the cork and fibers which are incidentally broken and finely comminuted to powder form during the differential pulverization of the bark.

The percentage composition of these three tissue components varies considerably with respect to the barks of different species of trees; with respect to the barks of different trees of the same species, depending on the age of the tree, geographical location, and other such factors; and even from different portions of the bole of the same tree. An indication of the variation in content of tissue components of different species of trees will be seen from inspection of Table I, below, showing a percentage analysis of three typical western coniferous trees, as follows: Douglas fir (Pseudotsuga taxifolia), Western hemlock (Tsuga heterophyle), white fir (Abies concolor).

TABLE I Douglas Fir Western (Pseudo- Hemlock White Fir Botanical Constituents of Bark tsuga (Tsuga (Abies tazz'folia) heterophyle) C'oncolor) Percent Percent 'Percent Cork 25 5 '40 Phloem:

A. Selerenehyma 1. Fiber 40 2. Stone Cells 45 .45 B. Parenchyma- 1. Mostly sieve cells 35 50 15 The analyses given in Table I, above, are but typical analyses and percentages of the components may vary greatly from one tree to another, or from one portion to another portion of the same tree. For instance, in, a

study made to determine the potential yield of Douglas fir cork, the bark from difierent trees or different portions of the same tree was segregated into four. grades determined by the thickness of the cork layers, as follows: A to /2 inch or more, $4 to inch, to hit; inch, and less than ,4 inch. The cork yield from the four grades, based on the averages of a large number of samples, was found to range from 45% to 20% The grade 1 bark having cork layers of A to /2 inch thickness was obtained mostly from the stumps of very old trees. The cork content in Abies concolor bark was found to .vary from about 6% in the case of trees of 10 inches orless in diameter to approximately 50% in trees from 12 to 16 inches in diameter, and then to decrease to as low in trees from 16 to 46 inches in diameter. g I

The bark components in forms suitable for the practice of the instant invention are obtainable by methods which rely upon the selective comminution of the bark constituents followed by the application of mechanical methods for separating the products of various particle size. Such methods are represented by those disclosed in Letters Patent Nos. 2,437,672 (granted March 16,

1948, to Herman W. Anway, for Method of Treating Bark), 2,446,551 (granted August 19 1948, toRobert D. Pauley, for Separation of Pure Bark Fiber From Finely Comminuted Bark) and 2,627,375 (granted February 3,

1953, to Bror L. Grondal and Calvin L. Dickinson, for

Separation of Bark Components); said Letters Patent having a common assignee with this application. These methods are based upon the discovery that when the whole bark is subjected to a pulverizing operation at a controlled moisture content, the non-fibrouscomponents of phloem are relatively friable as compared with the cork and bast fibers. The whole bark is', accordingly, subjected to one or more comminutingoperations at a controlled moisture content whereby the non-fibrous phloem is reduced to a powder, the fiber bundlesare opened up to release the individual fibers, but the relatively resistant aggregates of cork cells comprising the cork layers are not substantially reduced in size. There are thus produced three principal tissue components having difierent particle sizes, i. e., cork ultimate fibcr,.and

powdered phloem. These may be separated by. employ ing appropriate mechanical methods, such as screening,-

flotation, or air separation, but not without difiiculty, and fractions designated as pure able by such methods.

While the cork component obtained from the bark of coniferous trees resembles cork from the cork oak, it is quite different therefrom in chemical composition an in some physical properties. It has been established that the cork component from the bark of coniferous trees; is highly thermoplastic,'wher'eas' the cork of the corkoak" mean as pure as obtainis' not. ,Whereas temperatures of between about 450 F. auiabautpy .F-arermploued,inihemcommerciaLpro? duction of cork tile and cork board from Mediterranean cork, Douglas fir cork flows and becomes thermoplastic at temperatures slightly aliove 300 F. In fact, if it is I. heated to temperaturesof the order of about 430 F., it

chars and decomposes, providing further evidenee of the "findaniental"distinctidn betiveen these two products.

7 A significant difference? between the cork of coniferous trees and Mediterranean cork is observed in theirbulk densities. When sam'plesof Abies concolor, Douglas fir and Mediterranean cork were milled to approximately 14 rr'iesh size, the bulkdensity of Abies concolor was 15.3

pounds per cubic foot, of. Douglas fir cork was 11 .7

. pounds per cubic foot, and of Mediterranean cork was .3.5 pounds per cubic foot. -Mediterranean cork contains 20% to 30% lignin, whereas Douglas fir cork contains approximately 50% lignin as determined by the 72% 'sulfuric. acid method. Mediterranean.corkcontains 25% 1614076 Ifatty acids, whereas Douglas in cork contains approximately of these compounds. Mediterranean co contains 3% to 1 6% tannins and phlobaphenes, whe easoougn fir cor k contains 15% to of water s'oluble'tannins. Other characteristics of Douglas fir V chrkfare'that it contains approximately 9% ofwax; is approximately 65 soluble in 2% sodium hydroxide solu'tion', approximately 22% soluble in ether; its aqueous suspension has a 'p' I-I of 3.6; and it shows absorptive 1 e'activity with formaldehyde.

@Yarious bark fractions have been employed in the practice .of the instant invention. These were treated withanalkaline solution to render the cork and parenenymsxcempon tg reactive with an aldehyde. The cork fractionsso employed have ranged from substantially a :fpu're cork fraction which, by the Sink- Float method,

tests at about 80%hcork with the remainder substantially evenly divided between fiber and parenchyma tissue to a mixture of bark components consisting of approximateeork, 20% 'fiber and 70% parenchyma tissue. 7 f V fSINx-FLOAT nes'r ,"lffine grind the bark fraction a micro-pulverizer through a 100 mesh screen to frub'and 'abrade' thebark co i fit nents-apart."

1"2. Pr'epareth'ree volumetrically equal mixtures of carbon tetrachloride and benzene having densities of 1.380 g'./rnl,' 1,450 g. /ml. and 1.470 g./m 1; respectively.

3;"Mix 1by stirring until wet and then centrifuging an aliquot 'p'ortiorifof the fine ground bark component produiitof'step 1 into eachior the solutibns of step 2' .in' the ratio of 5 grams of bark component to 200 'ml. of solution vand allow toisettle overnight.

cork land'fibe'r content.

An adhesive composed of a bark fraction containing at least about 68% cork produced'plywood which met interior grade specifications; Barkfractions comprising less than about 68% cork provedto'be unsatisfactory as the principal ingredients in a caustic-formaldehydebark adesive. Since the fiber is an inert material, its presence hasno appreciable. effect on the treatmentof. thecork and parenchyma components with an alkali, oi the reaction' of the reacted'components with an aldehyde. 'When 4 ployed in such adhesives, the cork component and paren- .chymatissue-reactingawith-the alkaJi-tO form a reaction product which is reactive with the aldehyde. However, as appears hereafter, the resin produced from the parenchyma tissue is decidedly inferior to that produced from the cork.

In some of the experiments the formaldehyde was added as formalin. Commercial formalin contains by Weight about 37% formaldehyde, about 7% methanol, from 0.005 to 1% of formic acid, with the remainder made up of Water. If free alkali remains after thetreatment of cork andpowder itreacts with the-formic ,acid.

No upper ispiaced on thefsize of thecorkfthat can betreated with an alkaline solution ias the size is not a .criticalfactor. The cork is solublein an alkaline solution. The sizes of the comminuted cork affect only mesh screen. V

In this specification the reaction product of a mixture H of cork, which may contain parenchymatissue, and sodium hydroxide will ,beknown as reactive cork; -Itwill be understood .that as used :herein, the term sodium hydroxidis rfipl sentativeof any ofrthe alkaline reacting eompounds of the alkali metals. Reactive cork and reactiveparenchyma react with an aldehyde, e. g., formaldehyde, decreasing the formaldehyde concentration and increasing the viscosity of the suspension. The reaction proceeds rapidly to form a resinous material which may be employed inthe manufacture. of adhesives suitable for use in the manufacture of plywood.

I he formation of a resin by treating cork or amixture of cork and parenchymaztissue with an alkaline solution to obtain reactive cork and/or reactive cork and parenchyma and then treating the reactionproduct with i an aldehyde, involvesa large number of variables, such as the ratio of the cork to alkaline solution, the need for adding heat ,to the cork-alkaline mixture, the amount of aldehyde necessary to form a resin, the efiect of waxfree cork on the resin, and the'efiect of adding a phenolic mp und- The treatment of the cork or mixture of cork and parenchyma with an alkaline compound to obtain reactive cork and reactive parenchyma is one of the most important steps in the process, in that if the cork and parenchyma are not rendered reactive with an aldehyde there will be no resin.

A comparison of Examples I, H and III shows that the alkaline material used can vary from about 15% to 25% of the Weight of the cork. At the higher concentrations of alkaline material the cork-alkaline mixtures do not require the application of external heat to form a resin, but when a lesser amount .(e. g., about 15%) of.

alkaline material is'used external heat is required to make a resin having adhesive properties commensurate with those of a resin made with 20% or more or alkaline material. When substantially pure cork is treated with an alkaline solution the usage of alkaline material may be as much as 30%, for the reason that since cork reacts with "the alkali, the greater amount of cork permits use the reactive cork. On comparison of Examples I, VIII,

IX and X it is seen that the addition of a phenolic 0.0mpound to the reactive cork produces a much superior resin he? finesse e qne- Following Examples I through YII illustrate the eifect ie' il fisrs use-tramps bf lka ne q t ons' on cork as reflected in the manufacture of plywood adh sives, and also the effect of the variation of aldehyde. In Example VII the wax was first extracted from the cork. These results are summarized in following Table II.

TABLE II Example Components Parts Grade Plywood Cork 100 I I Na 25 Interior.

Paraformaldehyde 47 I Cor 100 II "aOH 20 Do.

Formaldehyde (Formalln) 43 Cork 100 III NaOH 15 Do.

Formaldehyde (Form 43 Cork. 100

IV NaOH 25 Do.

Formaldehyde (Formalin) 47 Cork 100 V {NaOH 25 D0.

garakriormaldehyde 1%;

vr NaOH 25 P 333 Paraformaldehyde- 70 Cork 100 VII {NaOH 25 Concrete. Paraformaldehyde 47 Example I In this experiment the sodium hydroxide was 25% by weight, based on the weight of the bark fraction compris ing 68% cork. The sodium hydroxide was dissolved in about 140 parts of water and about 100 pants of the bark fraction added to the hot alkaline solution, and mixed until the heat of reaction had been dissipated. Approximately 47 parts of paraformaldehyde in about 30 parts of water were mixed in the alkaline solution containing reactive cork until a smooth mixture was obtained. Sample Vs" plywood panels of A Douglas fir veneer were made with the resin and at an average dry shear of 173 pounds per square inch the average wood failure was 77%, with the plywood passing the two cycle soak test prescribed by the D. F. P. A. for interior grade plywood.

Example II In this experiment the sodium hydroxide was 20% by weight, based on the weight of the bark fraction comprising 68% cork, 20 parts of sodium hydroxide were dissolved in about 140 parts of water and the bark fraction added .to the hot alkaline solution and mixed until the heat of reaction had been dissipated. Approximately 117 parts of formalin (about 43% form-aldehyde based on the weight of the bark fraction) were mixed in the alkalicork dispersion containing reactive cork until a smooth mixture resulted. Sample plywood panels of A1" Douglas fir veneer were made and evaluated at 45 lb./ M d. g. l. and 55 lb./M d. g. l. The term lb./M d. g. 1. means pounds of glue per thousand square feet of double glue line, or pounds of glue per two thousand square feet of area between the veneers. At both 45 lb. and 55 lb. spreads the plywood passed the two cycle soak .test prescribed for interior grade glue.

Example 111 In this experiment the sodium hydroxide was 15% by weight based on the weight of the bark fraction (68% cork). 15 parts of sodium hydroxide were dissolved in about 140 parts of water and the bark fraction added. Instead of allowing the resulting mixture to cool, the alkali-bark mix was placed in a water bath at 200 F. for approximately 30 minutes. About 117 parts of formalin (43% formaldehyde based on the weight of the bark) were mixed in the cool alkali-bark dispersion containing reactive cork until a smooth mixture resulted. Sample plywood panels of Va" Douglas fir veneers were made and evaluated at 45 lb./M d. g. l. and 55 lb./M d. g. 1., and in each instance an interior grade plywood was produced.

Examples I, II and III show that by heating themixture of cork and an alkaline solution a less concentrated alkaline solution will produce a reaction product that is nearly equal to the product obtained when the cork is treated with a more concentrated alkaline solution and no external heat added.

The concentration of formaldehyde was varied over a wide percentage range based on the ratio of formaldehyde to. bark fraction, with the results indicating that comparable resins were obtained. The following examples illustrate the variation of formaldehyde concentration. In Example I the formaldehyde was about 47% by weight based on the weight of the bark fraction, and was added in the form of paraformaldehyde. In Example IV formaldehyde was added as formalin.

Example IV In .this example the sodium hydroxide was 25% by weight based on the weight of the bark (68% cork). 25 parts of sodium hydroxide were dissolved in about 140 parts of water and .the bark fraction added to the hot alkaline solution and mixed until the heat of reaction had been dissipated. Approximately 127 parts of formalin (about 47% formaldehyde based .on the weight of the bark fraction) were added to the alkali-bark dispersion containing reactive cork until a smooth mixture resulted. Sample plywood panels of Ms" Douglas fir veneer were made with the resin at a usage of 45 lb./M d. g. 1., resulting in an interior grade plywood.

Example V In this example the ratio of formaldehyde to bark fraction was lowered to about 23 formaldehyde based on the weight of the bark fraction. ide were dissolved in about 140 parts of water and about 100 parts of bark fraction (68% cork) added to the hot alkaline solution and mixed until the heat of reaction had been dissipated. Approximately 23 parts of paraformaldehyde (about 23% formaldehyde based on the Weight of the bark) in about 30 parts of water were mixed in the alkali-bark dispersion containing reactive cork until a smooth mixture was obtained. Sample plywood panels of Vs" Douglas fir were made with the resin at a usage of 45 lb./M. d. g. 1. resulting in an interior grade plywood.

Example VI In this example the ratio of formaldehyde to barkfraction was raised to about 70% formaldehyde based on the weight of the bark. 25 parts of sodium hydroxide were dissolved in about 140 parts of water and about parts of bark fraction (68% cork) added to the hot alkaline solution and mixed until the heat of reaction had been dissipated. Approximately 70 parts of paraformaldchyde (about 70% formaldehyde based on the weight of the bark fraction) in about 30 parts of water were mixed in the alkali-bark dispersion containing reactive cork until a smooth mixture was obtained. Sample plywood panels of A3" Douglas fir veneer were made with this resin at a usage of 45 lb./M. d. g. 1., resulting in -a plywood of ahnost concrete form quality.

The barks of coniferous trees contain various waxes and experiments were conducted to determine the effect on the resin by extracting the cork with benzene before adding the cork to the alkaline solution. The following Example VII illustrates this effect on the resulting resin.

Example VII The cork from coniferous tree bark was extracted with mixture was obtained. Sample plywood panels of 25 parts of sodium hydrox 14;" Douglas fir veneer were made with the resinat a usage of 45 lb,/M. d. g. 1., resulting in a concreteform plywood..

Example VII shows that extracted cork producesa resin superior to resins made from cork which is not wax free. The resins formedin-Examples I and IV when used as a plywood glue. gave' an interior grade plywood, while the resin in Example VII gave a concrete form plywood, a better grade. The extraction of cork with benzene to remove the waxes results in a better resin and the waxes can be recovered.

At the present time it is believed that the cork and parenchyma components contain phenolic-like structures. These phenolic-like structures, upontreatment with an alkaline solution, are rendered reactive with aldehydes to form resins. Examples I-VI illustrate compositions havingproperties similar to phenol-aldehyde resins.

In the" followingexperimenta'VIII, -IX and X, a phenolic compound from the group consisting of phenol,

xylenol, and cresol-was added to the alkaline dispersion containing reactive cork to determine the effect on the resin produced. The ratio of alkaline compound to the bark fraction, 25% of alkaline compound based on the weight'of the bark fraction, and the ratio of formalde hyde, 47% by weight based on the weight of the bark fraction, were maintained constant while only the" usage of phenolic compound was varied.

The addition of approximately by weight of a phenolic compound based on the weight of the bark fraction makes a superior resin to that formed by cork alone.

with unextractcd cork plus either phenol or cresol. xylenol, when added to reactive unextracted cork, produces an adhesive superior to an adhesive formed from wax-free cork, or when phenol and cresolare added to the reactive cork.

Following Table III illustrates theeflect of the addition of a phenolic-like compound to the resin:

Example VIII parts of sodium hydroxide were dissolved in about 140 parts of water, and about .100 parts of the bark fraction were added by stirring to the hot alkaline solution until the heat of reaction had been dissipated. 20 parts of phenol and approximately 47 parts of paraformaldehyde in about parts of water were added by stirring.

Sample plywood panels of /a" Douglas fir veneer were made with this resin at a usage of'45 lb./ M. d. g. 1., resulting in a concrete form plywood.

Example X Approximately 25 parts of sodium hydroxide were dissolved in about 140 parts of water, and about l00parts Wax-free cork can be used to make a resin} with about the same adhesive properties as can be made 'which the cork constitutes approximately 80% of the bark. Example XII illustrates the use of a bark fraction comprising approximately 70% parenchyma tissue, and shows a formulation having the largest amount of parenchyma tissue and the smallest amount of cork.

Example XI About 27 parts of sodium hydroxide were added to about 152 parts of water and 100 parts of a bark fraction comprising approximately 80% cork (by the sinkfloat.test; formerly estimated at 98% by visual methods) were stirred into the hot alkaline solution until the heat of reaction had been dissipated. About 109 parts of formalin (40%. formaldehyde by weight based on the weight of the cork) were mixed in the alkali-cork dispersion. The resin was tested as a plywood adhesive. The usage was varied from about 44 lb./M' deg. 1. to lb./M d. g. l. and the resulting plywood passed the 10 cycle soak test for an interior grade plywood.

Example XII About 27 parts or" sodium hydroxide were dissolved in approximately 152 parts of water and 100 parts of a bark fraction containing approximately parenchyma tissue powder, 20% fiber and 10% cork (formerly estimated as 9-1% powder, 1% fiber and 8% cork), stirred into the hot alkaline solution until the heat, of reaction'had been dissipated. About 109 par-ts of formalin (40% formaldehyde, by weight based on the weight of the bark fraction) were mixed-in the powder-alkali dispersion. The resin was tested as a plywood adhesive. The results of these tests indicated that a resin had been prepared but that its adhesive properties were unsatisfactory and decidedly inferior to those of a resin prepared from a bark fraction having a cork content of at least 68%.

Sodium hydroxide has been used in the examples as the basic reacting alkali metal compound for reaction with the bark fraction. Other basic reacting alkali metal and ammonium compounds may be substituted for the sodium hydroxide in equivalent amounts. Examples of such other'compounds are sodium carbonate, potassium hydroxide, potassium carbonate and ammonium hydroxide.

Plywood tests for Wet shear (WS) and wet wood failure (WF) have been made comparing these properties of adhesiveresins'made in accordance with the process of these examples using (1) the bark fraction commercially knoWnas Silvacon 383, containing about 68% cork, (2) pure bark fiber containingabout 3% cork, (3) pure bark .powder containing about 70% parenchyma tissue powder, 20% fiber and 10% cork and (4) .pure cork containing about cork. In each case the plywood used for testing was 3-ply DF plywood made in the same manner and under the same conditions. The

adhesive composition used in making the test: plywood was prepared from the following formulation dilfering only in the bark'fraction used:

TEST COMPOSITION J 600+ grns. H20 to spreading viscosity The results of tests for wet shear and wet'wood failure on each; type ofbark fraction are tabulated in the following table and plotted on'the grflphcomprising the of bark fraction comprising 68% cork were added 133L475 accompanying. drawing.

In the graph the percentage of cork in the bark component is plotted against the results of the Wet shear test in pounds per square inch in the lefthand (L. H.) ordinate and against percent wet wood failure in the righthand (R. H.) ordinate. In this latter test, the sample which has been subjected to the wet shear test is observed for determination of the proportion of the shear rupture that is attributable to the wood. The observations are visual and subject to personal inaccuracies. However, the test does provide a supplemental indication of the comparative quality of the adhesive as expressed in the estimated percent of wood failure. It will be noted by reference to the graph that the point for the wood failure representing Pure bark powder (No. 3 of the table) is off the curve. However, the mean curve through the four points has approximately the same characteristics as the wet shear curve which latter is based upon actual readings. Both of these curves show a more marked improvement in the properties of the adhesives in the region of the cork percentages above about 68% than those below that point.

Having now described my invention and the manner in which it may be used, what I claim as new and desire to protect by Letters Patent is:

1. A process for making a resin comprising dissolving a basic reacting compound in water, adding a bark component separated from the bark of a coniferous tree and containing at least about 68% of cork, stirring the mixture until the heat of reaction is dissipated and the bark component is dispersed and dissolved, adding while stirring an aqueous solution of an aldehyde selected from the group consisting of formaldehyde and paraformaldehyde, and reacting the mixture to produce a resin.

2. A process for making a resin comprising adding to an aqueous solution of a basic reacting compound of an alkali metal a commiuuted bark component separated from the bark of a coniferous tree and containing at least about 68% of cork, stirring the mixture until the heat of reaction is dissipated and the bark component is dispersed and dissolved, adding formaldehyde to the reaction mixture and reacting the resulting mixture to produce a resin.

3. A process for making a resin comprising dissolving a basic reacting compound in an alkali metal in from about 130 to about 150 parts of water, adding to the resulting solution about 100 parts of a bark component separated from the bark of a coniferous tree and containing at least about 68% of cork, stirring the mixture until the heat of reaction is dissipated and the bark component is dispersed and dissolved, adding while stirring a solution of from 20-70 parts of formaldehyde in from 30-90 parts of Water and reacting the mixture to produce a resin.

4. A process for making a resin comprising dissolving from -40 parts of a basic reacting compound of an alkali metal in from about 130 to about 150 parts of water, adding about 100 parts of a bark component separated from the bark of a coniferous tree and containing at least about 68% of cork, heating While stirring the resulting mixture to a temperature within the range of from about 150 F. to about 200 F. to disperse and dissolve the bark component, adding to the resulting reaction mixture from 20-70 parts of formaldehyde in from 30-90 parts of water and reacting the mixture to produce a resin.

5. A process for making a resin comprising dissolving a basic reacting compound in water, adding a bark component separated from the bark of a coniferous'tree and containing at least about 68% of cork, stirring the mixture until the heat of reaction is dissipated and the bark component is dispersed and dissolved, adding to the reaction mixture a phenolic compound selected from the group consisting of phenol, cresol and xylenol, adding an aldehyde selected from the group consisting of formaldehyde and paraformaldehyde, and reacting the resulting mixture to produce a resin.

6. A process for making a resin comprising dissolving from 1040 parts of a basic reacting compound in water, adding about parts of a bark component separated from the bark of a coniferous tree and containing at least about 68% of cork, stirring the mixture until the heat of reaction is dissipated and the bark component is dispersed and dissolved, adding to the reaction mixture up to 30 parts of a phenolic compound selected from the group consisting of phenol, cresol and xylenol, adding While stirring from about 2070 parts of formaldehyde and reacting the resulting mixture to produce a resin.

7. A resin product consisting of the reaction product of an aldehyde selected from the group consisting of formaldehyde and paraformaldehyde and a component of the bark of a coniferous tree consisting of at least about 68% of cork, said component having been rendered reactive with aldehydes by treating it with a solution of a basic reacting compound and said resin product having been produced in accordance with the process of claim 1.

8. A resin product consisting of the reaction product of formaldehyde and a component of the bark of a coniferous tree consisting of at least about 68% of cork, said component having been rendered reactive with aldehydes by treating it with a solution of a basic reacting alkali metal compound and said resin product having been produced in accordance with the process of claim 2.

9. A process for making a resin comprising adding to an aqueous solution of a basic acting compound of an alkali metal wax free cork obtained as a product separated from the barks of coniferous trees and having its wax content extracted therefrom, stirring said mixture until the heat of reaction is dissipated and the bark component is dispersed and dissolved, adding formaldehyde in Water and reacting the mixture to make a resin.

10. A process for making a resin comprising adding to an aqueous solution of a basic acting compound of an alkali metal a benzene extracted wax free cork obtained as a product separated from the barks of coniferous trees, stirring said mixture to disperse and dissolve the bark component and simultaneously cooling the same, thereupon adding formaldehyde to the alkali-cork reaction product and reacting the mixture to make a resin.

References Cited in the file of this patent UNITED STATES PATENTS 

5. A PROCESS FOR MAKING A RESIN COMPRISING DISSOLVING A BASIC REACTING COMPOUND IN WATER, ADDING A BARK COMPONENT SEPARATED FROM THE BARK OF A CONIFEROUS TREE AND CONTAINING AT LEAST ABOUT 68% OF CORK, STIRRING THE MIXTURE UNTIL THE HEAT OF REACTION IS DISSIPATED AND THE BARK COMPONENT IS DISPERSED AND DISSOLVED, ADDING TO THE REACTION MIXTURE A PHENOLIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF PHENOL, CRESOL AND XYLENOL, ADDING AN ALDEHYDR SELECTED FROM THE GROUP CONSISTING OF FORMALDEHYDE AND PARAFORMALDEHYDE, AND REACTING THE RESULTING MIXTURE TO PRODUCE A RESIN. 